fosfestrol sodium

Fosfestrol is the diphosphate ester of a synthetic, nonsteroidal form of estrogen. Fosfestrol is an antineoplastic agent used to treat hormone-sensitive tumors, especially prostate cancer. Fosfestrol is a prodrug of diethylstilbestrol that is activated in the target cells. A well-known teratogen and carcinogen, diethylstilbestrol inhibits the hypothalamic-pituitary-gonadal axis, thereby blocking the testicular synthesis of testosterone, lowering plasma testosterone, and inducing a chemical castration. Side effects include among others liver damage, nausea, fluid retention, arterial and venous thrombosis, congestive heart failure, pulmonary embolism, pulmonary thrombosis, bone marrow toxicity, mental disturbances, impotence, breast enlargement in male, withdrawal bleeding, and bone pain. There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits. — NCATS